Magnesium Prophylaxis for the Prevention of New-Onset Atrial Fibrillation in Critically Ill Patients (ATOMIC)

September 17, 2025 updated by: Dr. Stephanie Sibley

Parenteral Magnesium Prophylaxis for the Prevention of New-Onset Atrial Fibrillation in Critically Ill Patients - a Pilot Feasibility Study

A double-blind, multi-centre, randomized, placebo-controlled, feasibility pilot trial in the prevention of new onset atrial fibrillation of critically ill patients admitted to an ICU.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Most studies of new onset atrial fibrillation (NOAF) in critical illness focus on treatment of this arrhythmia but this innovative study will focus on prevention. Parenteral Mg is a low cost and readily available treatment that may be beneficial for reducing the incidence of NOAF in critically ill patients, with the potential to improve patient centred outcomes and provide a cost effective prophylaxis. The main outcome of this study is to determine if it is feasible to conduct a randomized controlled trial comparing parenteral magnesium sulfate with placebo for the prophylaxis of new onset atrial fibrillation in critically ill patients.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
200

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Canada
    • Ontario
      • Hamilton, Ontario, Canada, L8N 1Y3
        • Not yet recruiting
        • St Joseph's Healthcare Hamilton
        • Contact:
          • Dr. Deborah Cook, MD
      • Kingston, Ontario, Canada, K7L2V7
        • Recruiting
        • Kingston Health Sciences Centre
        • Principal Investigator:
          • Stephanie Sibley, MD
        • Contact:
      • Ottawa, Ontario, Canada, K1H 8L6
        • Not yet recruiting
        • The Ottawa Hospital - General Campus
        • Contact:
          • Dr. Andrew Seely, MD
      • Ottawa, Ontario, Canada, K1Y 4E9
        • Not yet recruiting
        • The Ottawa Hospital - Civic Campus
        • Contact:
          • Andrew Seely, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria

  1. Age ≥18 years;

  2. Admitted to an ICU with one or more of the following:

    1. Non-invasive ventilation (including CPAP, Bipap and high flow oxygen (>10L/min) or invasive mechanical ventilation with an expected duration >24 hours for respiratory failure (hypercarbic or hypoxic)
    2. Vasopressor or inotropic support with an expected duration of >24 hours
    3. Cardiac arrest
  3. Continuous cardiac monitoring.

Exclusion Criteria

  1. Receiving ICU intervention (Non-invasive ventilation (including high flow nasal canula), invasive mechanical ventilation or inotropic support) for >18 hours
  2. Receiving IMV for airway protection only (for example, isolated head trauma)
  3. Active atrial fibrillation at the time of enrolment
  4. On oral or continuous infusion of Amiodarone
  5. Unlikely to survive >24 hours or palliative patients
  6. Cardiac surgery patients
  7. Patients requiring parenteral magnesium therapy (e.g. pre-eclampsia, asthma)
  8. Patients receiving dialysis
  9. Positive pregnancy test (females <50 years old)
  10. Previously enrolled in this trial
  11. Treating physician refuses enrollment

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Magnesium Sulfate
4g Magnesium sulfate (100mL) BID, given intravenously over 2 hours, for a total of 10 doses
Drug: Magnesium sulfate
Intravenous Magnesium sulfate
Placebo Comparator: 0.9% NaCl
100mL 0.9% NaCl BID, given intravenously over 2 hours, for a total of 10 doses
Drug: Placebo
0.9% NaCl

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
RCT Feasibility
Time Frame: 90 days
To assess feasibility of patient recruitment, randomization procedures, intervention and data collection and measure protocol adherence. Protocol adherence ≥ 90% (We define protocol adherence as administration of first dose of study drug within 18 hours (+1hr window) of 1st ICU intervention (life sustaining therapy) delivery of all additional
90 days
RCT Feasibility
Time Frame: 90 days
Recruitment rate of ≥ 2 patients/month/ICU
90 days

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Equipoise and Feasibility
Time Frame: 365 days
Physician willingness to recruit patients in the setting of existing electrolyte replacement protocols; effectiveness of blinding; proportion of patients who meet eligibility criteria of those admitted to ICU; proportion of eligible patients for whom consent is obtained; proportion of patients who re-consent when they regain capacity for those randomized under the deferred consent model; proportion of patients lost to follow-up; time for research personnel to complete study related tasks.
365 days
Acute Care Outcomes
Time Frame: 28 days
Total number of patients developing AF within 28 days of enrolment (AF will be defined as at least 30 seconds of NOAF detected by cardiac monitoring or ECG); Use of rate and rhythm controlling agents, vasoactive agents, diuretics, steroids, anticoagulants, bleeding events, thromboembolic events (as defined in the 2018 Canadian Stroke Best Practices Guideline1; these will be adjudicated by a neurologist blinded to study groups), persistent organ dysfunction, mortality
28 days
Hospital Outcomes
Time Frame: 28 days
Days alive and ventilator free, ICU length of stay, and hospital length of stay.
28 days
Adverse Events
Time Frame: 28 days
Adverse drug reactions including bradycardia (HR <60 bpm); severe bradycardia (HR <50 bpm); clinically significant bradycardia (bradycardia requiring inotropes, vasopressors, external pacing, temporary pacemaker, or discontinuation of the trial medication); hypotension (MAP< 65mmHg, or systolic blood pressure [SBP]>20mmHg below admission baseline); clinically significant hypotension (hypotension requiring vasopressors, fluid administration, or discontinuation of the trial medication) while the study drug is being infused.
28 days
Functional Outcomes
Time Frame: 365 days
EQ-5D score, death after discharge.
365 days

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Adverse Events
Time Frame: 90 days
Adverse patch reactions (skin irritation)
90 days
Adverse Events
Time Frame: 90 days
bradycardia (HR <60 bpm); severe bradycardia (HR <50 bpm); clinically significant bradycardia (bradycardia requiring inotropes, vasopressors, external pacing, temporary pacemaker, or discontinuation of the trial medication)
90 days
Adverse Events
Time Frame: 90 days
hypotension (MAP< 65mmHg, or systolic blood pressure [SBP]>20mmHg below admission baseline); clinically significant hypotension (hypotension requiring vasopressors, fluid administration, or discontinuation of the trial medication)
90 days
Functional Outcomes
Time Frame: 365 days
Clinical Frailty Score
365 days
Functional Outcomes
Time Frame: 365 days
EuroQoL EQ-5D
365 days
Functional Outcomes
Time Frame: 365 days
death after discharge
365 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Dr. Stephanie Sibley

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Canadian Institutes of Health Research (CIHR)
Southeastern Ontario Academic Medical Organization (SEAMO)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Stephanie Sibley, MD, Queen's University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 20, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 1, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 15, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 12, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 25, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 22, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 17, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ATOMIC

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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